>>527315694
you can drop them from rewards in t17s (always use unending nightmare bros) OR you can drop them from unique monsters in t15+ if you have the atlas node that gives a tiny chance for unique mobs to drop a cluster, which im pretty sure is even better.
theres a strategy that involves adding titanic rogue exile giants to a map, killing them on a ritual altar and then bagging them up in a ritual vessel. if you pair that with delirium + the node that gives unique mobs a chance to drop clusters and deli orbs, you end up also dropping a ton of deli orbs and ilvl 84 clusters while youre farming the blood filled vessels. im pretty sure that strategy gives infinite div/hr in trade league because nobody knows about it